1. Field
Embodiments of the present invention relate to an organic light emitting diode display including a thin film organic layer.
2. Description of Related Art
An organic light emitting diode display (OLED display) is a self-emission type display device that displays an image using organic light emitting diodes (OLEDs) that emit light. The OLED display exhibits excellent properties such as low power consumption, high luminance, and high speed of response, and thus has drawn attention as a display device of the next generation.
The OLED generally includes an anode and a cathode, which are opposed to each other, with an organic layer disposed therebetween. Further, the organic layer includes an organic light emitting layer. Holes and electrons are respectively supplied from the anode and the cathode into an organic light emitting layer, and then combined with each other therein to form excitons. The OLED emits light by energy generated when the excitons fall from an excited state to a ground state.
A microcavity may be used to more efficiently extract light generated from the organic light emitting layer, thereby improving luminance efficiency. The microcavity utilizes a principle in which, when light is repeatedly reflected off a reflective layer (e.g., an anode electrode) and a transflective layer (e.g., a cathode electrode) that are a predetermined distance (i.e., an optical path length) apart from each other, a strong interference effect occurs between the reflected light so that light of a predetermined wavelength is amplified and light of other wavelengths is cancelled out. Accordingly, frontward color reproducibility and luminance of the OLED display are improved.
In order to bring about the microcavity effect, distances between the anode and cathode of red, green, and blue OLEDs are respectively determined according to red, green, and blue wavelengths, and a thickness of the organic layer disposed between the anode and the cathode is also determined according to the respective wavelengths. However, when the organic layer is thickly formed to achieve the microcavity effect, more organic materials are required, thereby increasing the manufacturing cost of OLED displays.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the technology disclosed herein, and as such the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of subject matter disclosed herein.